Alizarin S (Alizarin Red S; sodium alizarin sulfonate) is a benchmark stain for detecting calcium deposits and matrix mineralization across histology, osteogenesis, and tissue-engineering workflows, with standardized protocols and quantitative readouts used globally. Histor-ically derived from madder root and later displaced by chemical syn-thesis, it remains a staple reagent supplied by major vendors. At the same time, growing lab and diagnostic activity continues to expand demand for stains and reagents. Conventional dye manufacture car-ries well-documented environmental burdens from anthraquinone ef-fluents, reinforcing the case for cleaner production models. Emerging bio-based approaches – including engineered or elicited production of anthraquinones – offer a pathway to consistent quality, lower foot-print, and improved supply security for critical stains like Alizarin S.